Effect of prostaglandins A(2), E(1), F(2 alpha)and latanoprost on cultured human iridal melanocytes.

The effect of various prostaglandins on the growth, melanogenesis and dendrification of cultured iridal melanocytes were studied. Iridal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor (complete medium). The iridal melanocytes were plated into multiple well plates and cultured with complete medium, cAMP-deleted medium with or without various prostaglandins at different concentrations. After 5-7 days, the numbers of cells and dendrites were counted and melanin content was measured and compared to controls. Prostaglandin A(2)and E(1)stimulated growth, melanogenesis and dendrification of cultured iridal melanocytes in cAMP-deleted medium. Prostaglandin F(2 alpha), PhXA85 and latanoprost showed no effect under similar experimental conditions. These results indicate that prostaglandin A(2)and E(1)stimulate growth and differentiation of iridal melanocytes through the activation of cAMP system. Failure of stimulation of melanogenesis of iridal melanocytes by prostaglandin F(2 alpha)and PhXA85 in vitro may be related to a different second messenger system activated by these prostaglandins and the selective stimulating effect of these prostaglandins on iridal melanocytes from mixed-colored irides.